How to use the body fat calculator
Choose your units and sex, then enter your height, weight and tape measurements of your neck and waist. Women also enter their hip measurement. The calculator estimates your body fat percentage, the weight of fat and lean mass, and the category you fall into.
How to measure
- Neck: just below the larynx (Adam's apple), with the tape sloping slightly down to the front.
- Waist: men at the navel, women at the narrowest point, after breathing out normally.
- Hips (women): around the widest part of the buttocks.
Keep the tape level and snug against bare skin without compressing it, and take each measurement twice to check.
The US Navy formula
For men: 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450. For women, the hip measurement is added to the waist and different constants are used. All measurements are in centimeters.
Body fat categories
Typical ranges from the American Council on Exercise: men, athletes 6–13%, fitness 14–17%, average 18–24%, obese 25% and above; women, athletes 14–20%, fitness 21–24%, average 25–31%, obese 32% and above.
How accurate is it?
Tape methods are usually within 3 to 4 percentage points of lab methods such as DEXA scans. They are best for tracking change over time, using the same technique each time.
Frequently asked questions
What is a healthy body fat percentage?
For most adults, about 14% to 24% for men and 21% to 31% for women is considered healthy.
Is body fat percentage better than BMI?
It tells you more about body composition, because BMI cannot tell muscle from fat. Using both gives a fuller picture.